1. Field of the Invention
The present invention relates to a magnetic resonance imaging apparatus that takes an image of a subject by collecting data about the inside of the subject by using magnetic resonance phenomenon, and a scanning-condition setting method.
2. Description of the Related Art
Conventionally, a magnetic resonance imaging apparatus is an apparatus that images an arbitrary cross section of a subject, such as a human body, by using various contrasts between tissues. Such magnetic resonance imaging apparatus performs imaging by executing a procedure so-called a pulse sequence, which sequentially defines events representing timing of application of a radio-frequency pulse or a gradient magnetic field pulse, and timing of data collection.
An operator of the magnetic resonance imaging apparatus appropriately sets various scanning parameters prior to a scan, and obtains information required for an examination, such as contrast, Signal to Noise ratio (SN ratio), spatial resolution, flow velocity, and diffusion. The scanning parameters include, for example, a Repetition Time (TR), Echo Time (TE), the number of matrices, Field of View (FOV), the number of slices, and slice thickness.
FIG. 11 is a schematic diagram that depicts an example of a user interface for editing scanning parameters according to a conventional magnetic resonance imaging apparatus. FIG. 11 depicts a scanning-condition edit screen including various scanning parameters as edit items. The operator sets a value of a required scanning parameter by inputting a numerical value or operating a user interface, such as a slider or a button, on the scanning-condition edit screen shown in FIG. 11.
Additionally to the scanning parameters described above, the operator edits scanning conditions, such as an imaging method (type of pulse sequence, for example, spin echo, or Echo Planar Imaging (EPI)), the type of a prepulse, such as a fat suppression pulse or an inversion pulse, the number of prepulses, the order of prepulses, and the order of slice excitation, in accordance with a purpose. As a technology for confirming spatial arrangement of such prepulses and scanning pulses, there is a technology of displaying a slice region on a positioning image (for example, see JP-A 2003-290171 (KOKAI)). A positioning image used in the technology is called a graphic locator, for example.
However, according to the conventional technology described above, the operator can confirm spatial arrangement of a prepulse or a scanning pulse, but cannot confirm temporal order of the prepulses or the scanning pulses. In other words, according to the conventional technology, when changing a scanning condition, the operator cannot obtain information that influences an image to be obtained, for example, timing of collection of data at a target scan position, the type of each prepulse to be applied, the order and the frequency of application of prepulses.